Metal-Organic Framework-Derived Fe-Doped Co1.11 Te2 Embedded in Nitrogen-Doped Carbon Nanotube for Water Splitting.

A rational design is reported of Fe-doped cobalt telluride nanoparticles encapsulated in nitrogen-doped carbon nanotube frameworks (Fe-Co1.11 Te2 @NCNTF) by tellurization of Fe-etched ZIF-67 under a mixed H2 /Ar atmosphere. Fe-doping was able to effectively modulate the electronic structure of Co1.11 Te2 , increase the reaction activity, and further improve the electrochemical performance. The optimized electrocatalyst exhibited superior hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in an alkaline electrolyte with low overpotentials of 107 and 297 mV with a current density of 10 mA cm-2 , in contrast to the undoped Co1.11 Te2 @NCNTF (165 and 360 mV, respectively). The overall water splitting performance only required a voltage of 1.61 V to drive a current density of 10 mA cm-2 . Density function theory (DFT) calculations indicated that the Fe-doping not only afforded abundant exposed active sites but also decreased the hydrogen binding free energy. This work provided a feasible way to study non-precious-metal catalysts for an efficient overall water splitting.